It is known to use a temperature control circuit, e.g. in the form of a PI or PID controller (PI=Proportional-Integral, PID=Proportional-Integral-Differential) for temperature stabilization in detector elements. The actual value of the controller is ascertained via a temperature sensor, the desired value is predefined in accordance with the desired temperature. Either a heating and a cooling unit or a combined heating and cooling unit, such as e.g. a Peltier element, acts as an actuator. Control is also possible using only one heating or one cooling unit if the other control direction is realized by the flow of the heat energy to a heat reservoir in the surrounding area.
Likewise it is known that a feed forward control can be implemented to reduce the control deviation of a controller. For example, reference is made to the publication DE 10 2005 061 358 A1 in which temperature stabilization takes place on the basis of temperature monitoring. A disadvantage of such a method is that on account of the inertia of the temperature measurement, control of the system can only intervene when the system has already heated up, in other words, a temperature rise has been recorded in the ASIC. As a result a response time is produced via the thermal inertia of the system, during which the temperature cannot be kept stable. Depending on the thermal inertia, the actual temperature may for a short time deviate from the desired temperature to a greater or lesser extent. This effect is particularly problematic where there are sudden, strong increases in the loaded radiation intensity, as are inevitable in computer tomography. The signal behavior of the detector changes for a short time as a result of this, which can ultimately result in artifacts in the image data which have arisen on the basis of measurement data ascertained with the detector.
In addition, reference is made to the publication WO 2005/116692 A2 identified in the examination procedure. The disclosure relates to a method for the stabilization of the signals generated by a scintillation detector for the measurement of radiation by the radiation at least partially absorbed in the detector and dependent on the operating temperature of the detector, wherein the temperature-dependent calibration factor K is determined on the basis of the waveform shape of the signals generated by the radiation to be measured itself. Only a calibration of the measured signals is therefore performed here.